From 468fe4196d522c947b9f348a6754a8067f3853f1 Mon Sep 17 00:00:00 2001
From: Igor Laevsky <igor.laevsky@jetbrains.com>
Date: Fri, 30 Jul 2021 15:12:45 +0300
Subject: [PATCH] WASM: Implement string.compareTo and string.subSequence

---
 .../stdlib/wasm/builtins/kotlin/String.kt     | 22 ++++++++++++++-----
 libraries/stdlib/wasm/src/kotlin/Math.kt      |  2 +-
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/libraries/stdlib/wasm/builtins/kotlin/String.kt b/libraries/stdlib/wasm/builtins/kotlin/String.kt
index a5fb6568dec..c6682cc4814 100644
--- a/libraries/stdlib/wasm/builtins/kotlin/String.kt
+++ b/libraries/stdlib/wasm/builtins/kotlin/String.kt
@@ -6,6 +6,7 @@
 package kotlin
 
 import kotlin.wasm.internal.*
+import kotlin.math.min
 
 /**
  * The `String` class represents character strings. All string literals in Kotlin programs, such as `"abc"`, are
@@ -31,16 +32,25 @@ public class String internal constructor(internal val chars: CharArray) : Compar
      */
     public override fun get(index: Int): Char = chars[index]
 
-    public override fun subSequence(startIndex: Int, endIndex: Int): CharSequence =
-        TODO("todo")
+    public override fun subSequence(startIndex: Int, endIndex: Int): CharSequence {
+        return String(chars.sliceArray(startIndex until endIndex))
+    }
 
-    public override fun compareTo(other: String): Int =
-        TODO("todo")
+    public override fun compareTo(other: String): Int {
+        val len = min(this.length, other.length)
+
+        for (i in 0 until len) {
+            val l = this[i]
+            val r = other[i]
+            if (l != r)
+                return l - r
+        }
+        return this.length - other.length
+    }
 
     public override fun equals(other: Any?): Boolean {
         if (other is String)
-            return chars.contentEquals(other.chars)
-            //return this.compareTo(other) == 0
+            return this.compareTo(other) == 0
         return false
     }
 
diff --git a/libraries/stdlib/wasm/src/kotlin/Math.kt b/libraries/stdlib/wasm/src/kotlin/Math.kt
index 61843481e38..48d6272c640 100644
--- a/libraries/stdlib/wasm/src/kotlin/Math.kt
+++ b/libraries/stdlib/wasm/src/kotlin/Math.kt
@@ -913,7 +913,7 @@ public actual fun abs(n: Int): Int = TODO("Wasm stdlib: Math")
  * Returns the smaller of two values.
  */
 @SinceKotlin("1.2")
-public actual fun min(a: Int, b: Int): Int = TODO("Wasm stdlib: Math")
+public actual fun min(a: Int, b: Int): Int = if (a < b) a else b
 
 /**
  * Returns the greater of two values.